Drive device for an ignition distributor for an internal combustion engine

ABSTRACT

Device for connecting the camshaft of an internal combustion engine to the driving shaft of an ignition distributor. The device comprises a driving gear on the camshaft and a driven gear connected to rotate the driving shaft. The driving gear has helical teeth and the driven gear straight teeth which are parallel to its axis of rotation and meshed with the helical teeth. The driven gear has an axis of rotation which is inclined relative to a plan perpendicular to the axis of rotation of the driving gear.

United States Patent [19'] Froumajou Oct. 9, 1973 DRIVE DEVICE FOR AN IGNITION DISTRIBUTOR FOR AN INTERNAL COMBUSTION ENGINE [75] Inventor: Armand Froumajou, Pontoise,

France [73] Assignee: Automobiles Peugeot,Paris; Regie Nationale Des Usines Renault,

Billancourt, both of France [22] Filed: Feb. 18, 1972 [21] Appl. No.: 227,459

[30] Foreign Application Priority Data Apr. 30, 1971 France 7115579 [52] U.S. Cl l23/146.5 A [51] Int. Cl. F02p 7/00 [58] Field of Search 123/1465 A; 74/412 [56] References Cited UNlTED STATES PATENTS 3,662,726 5/1972 l-laskew 123/1465 1,591,424 7/1926 Kent 123/1465 A 1,616,428 2/1927 Ringwald 123/1465 A 3,262,331 7/ 1966 Breuer 2,238,649 4/1941 Kishline 123/1465 A Primary Examiner-Laurence M. Goodridge Assistant Examiner-Cort Flint Attorney-Robert S. Swecker [57] ABSTRACT Device for connecting the camshaft of an internal combustion engine to the driving shaft of an ignition distributor. The device comprises a driving gear on the camshaft and a driven gear connected torotate the driving shaft. The driving gear has helical teeth and the driven gear straight teeth which are parallel to its axis of rotation and meshed with the helical teeth. The driven gear has an axis of rotation which is inclined relative to a plan perpendicular to the axis of rotation of the driving gear.

6 Claims, 2 Drawing Figures DRIVE DEVICE FOR AN IGNITION DISTRIBUTOR FOR AN INTERNAL COMBUSTION ENGINE The present invention relates to a drive device for an ignition distributor driven by the camshaft of an internal combustion engine.

It is known that in an internal combustion engine having a controlled ignition the ignition distributor is usually driven by the camshaft through a couple of gears affording a velocity ratio of unity. As for reasons of location the axis of the distributor and the axis of the camshaft are perpendicular or practically perpendicular, helical gears are used for the transmission of the motion. Now, owing to cyclic variations in the torque due to the effort required to open the valves, the camshaft docs not have a strictly constant speed of rotation throughout its cycle. Consequently, there is a continuous variation in the direction of the action of the driving gear on the driven gear and, owing to the inclination of the teeth of the driven gear and unavoidable play, this results in slight alternating helical displacements along the axis of the ignition distributor. These movements, which are superimposed on the general movement of rotation, have an effect which offsets the ignition point and tends to diminish the efficiency of the combustion and increase the emission of pollutant products.

-An object of the present invention is to remedy this drawback and avoid any axial reaction on the shaft of the ignition distributor so as to avoid practically any effect on the ignition timing relative to the optimum setting.

The invention provides a drive device for an ignition distributor and adapted to be driven by a camshaft, comprising a driving gear having helical teeth integral with the camshaft and a driven gear integral with the contact maker, wherein the axis of the driven gear is inclined with respect to a plane perpendicular to the axis of the driving gear and the driven gear has straight teeth which are parallel to its axis of rotation and cooperate with the teeth of the driving gear which are helical teeth.

Owing ,to this arrangement, sliding can occur between the teeth of the two gears so that it is possible to absorb the cyclic variations in the speed of rotation of the camshaft and avoid producing an axial reaction on the contact maker.

Further features and advantages of the invention will be apparent from the ensuringdescription with reference to the accompanying drawing.

ln the drawing FIG. 1 is a side elevational view, with a part cut away, of an embodiment in which the driven gear is directly mounted on the shaft of the ignition distributor, and

FIG. 2 is a side elevational view, with a part cut away, of a modification in which the distributor is driven in the known manner by means through a dog.

FIG. I shows a camshaft 1 having an axis X-X carrying a driving gear 2 adapted to drive an ignition distributor 3 whose shaft 4 is provided with a driven gear 5. The axis YY of the ignition distributor makes with a plane P perpendicular to the axis of the camshaft an angle a between, for example, 20 and 50. The gear 2 has helical teeth co-operating with straight teeth on the gear 5.

As explained hereinbefore, owing to this relative disposition of the axes X-X and YY and to the utilization of a gear 5 having straight teeth parallel to the axis YY, a limited amount of sliding is allowed between the teeth of the two gears which is sufficient to eliminate any axial force on the distributor and consequently avoid small helical alternating movements which are superimposed on the movement of rotation when the driven gear has helical teeth.

In this way, there is ensured an improved timing of the ignition and consequently an improved efficiency in the combustion and a notable reduction in the percentage of pollutant products contained in the exhaust gases.

In the modification shown in FIG. 2, the manner of driving is the same as in FIG. I but the driven gear is formed on a sleeve 6 journalled in two bearing portions 7, 7" of the housing 7. The sleeve 6 is connected to rotate with the shaft of the distributor 3 through a tongueand-groove coupling 8, or any other suitable means. The operation and the advantages obtained are the same as those of the embodiment shown in FlG. 1.

Having now described my invention what I claim as new and desire to secure by Letters Patent is z I. A device for driving the contact maker of an ignition distributor of an engine having a camshaft, comprising a driving gear having helical teeth for connection to the camshaft so as to be driven by the camshaft, a driven gear meshed with the driving gear, a shaft rotatably mounted and connected to the driven gear so as to be rotated by the driven gear, said shaft being for connection to said contact maker for driving said contact maker, the driven gear having an axis of rotation which is inclined relative to a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears, the driven gear having straight teeth which are parallel to said axis of rotation and are meshed with said helical teeth.

2. A device for driving the contact maker of an ignition distributor of an engine having a camshaft, comprising a driving gear having helical teeth for connection to the camshaft so as to be driven by the camshaft, a driven gear meshed with the driving gear, a shaft rotabably mounted and connected to the driven gear so as to be rotated by the driven gear, said shaft being for connection to said contact maker for driving said contact maker, the driven gear having an axis of rotation which makes an angle of 20-50 with a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears, the driven gear having straight teeth which are parallel to said axis of rotation and are meshed with said helical teeth.

3. A device as claimed in claim 2, wherein said shaft is the drive shaft of said contact maker.

4. A device as claimed in claim 2, comprising a housing, said shaft being integral with said driven gear and journalled in said housing, and coupling means being associated with said shaft for connecting it to said contact maker.

5. An internal combustion engine having a controlled ignition comprising a camshaft and an ignition distributor having an actuating input shaft, a driving gear carried by the camshaft and having helical teeth, a driven gear carried by the input shaft 'so that the camshaft can rotate the input shaft, the axis of rotation of the driven gear being inclined with respect to a plane which is perpendicular to the axis of rotation of the driving gear rotate the input shaft, the axis of rotation of the driven gear making an angle of 20-50 with a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears and the driven gear having straight teeth which are parallel to its axis of rotation and mesh with the helical teeth on the driving gear. 

1. A device for driving the contact maker of an ignition distributor of an engine having a camshaft, comprising a driving gear having helical teeth for connection to the camshaft so as to be driven by the camshaft, a driven gear meshed with the driving gear, a shaft rotatably mounted and connected to the driven gear so as to be rotated by the driven gear, said shaft being for connection to said contact maker for driving said contact maker, the driven gear having an axis of rotation which is inclined relative to a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears, the driven gear having straight teeth which are parallel to said axis of rotation and are meshed with said helical teeth.
 2. A device for driving the contact maker of an ignition distributor of an engine having a camshaft, comprising a driving gear having helical teeth for connection to the camshaft so as to be driven by the camshaft, a driven gear meshed with the driving gear, a shaft rotatably mounted and connected to the driven gear so as to be rotated by the driven gear, said shaft being for connection to said contact maker for driving said contact maker, the driven gear having an axis of rotation which makes an angle of 20*-50* with a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears, the driven gear having straight teeth which are parallel to said axis of rotation and are meshed with said helical teeth.
 3. A device as claimed in claim 2, wherein said shaft is the drive shaft of said contact maker.
 4. A device as claimed in claim 2, comprising a housing, said shaft being integral with said driven gear and journalled in said housing, and coupling means being associated with said shaft for connecting it to said contact maker.
 5. An internal combustion engine having a controlled ignition comprising a camshaft and an ignition distributor having an actuating input shaft, a driving gear carried by the camshaft and having helical teeth, a driven gear carried by the input shaft so that the camshaft can rotate the input shaft, the axis of rotation of the driven gear being inclined with respect to a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears, and the driven gear having straight teeth which are parallel to its axis of rotation and mesh with the helical teeth on the driving gear.
 6. An internal combustion engine having a controlled ignition comprising a camshaft and an ignition distributor having an actuating input shaft, a driving gear carried by the camshaft and having helical teeth, a driven gear carried by the input shaft so that the camshaft can rotate the input shaft, the axis of rotation of the driven gear making an angle of 20*-50* with a plane which is perpendicular to the axis of rotation of the driving gear and which passes thru the point of contact between the two gears and the driven gear having straight teeth which are parallel to its axis of rotation and mesh with the helical teeth on the driving gear. 